Faker.js: Add `name.middleName` property

[Deilan]

Please add name.middleName property.

[Marak]

Sounds good, a PR would be welcome.

[tomdaniels]

hey, @Marak if you still need a hand I should be able to help with this. Was the intention to use the same data set that was used for name.firstName or a new definitions.middle_name array altogether?

[Marak]

@tomdaniels

I think in most cases we can just use name.firstName to generate middle names? I'm not sure 100% sure.

I believe some locales require gendered middle names ( such as ru ), so this might be cross-cutting with that.

If you have time please check out master and see what we can do.

Thank you for your feedback.